Update PATTERNS_PATH, resolves issue #8

[tdunlap607]

As mentioned by @SecurityRepo in issue #8, the tool would not return any potential vulnerabilities when used as a command-line tool. When using git-vuln-finder as a library, I received the error message:

File ".../venv/lib/python3.8/site-packages/git_vuln_finder/vulnerability.py", line 21, in find_vuln
    m = pattern.search(commit.message)
AttributeError: 'collections.defaultdict' object has no attribute 'search'

The issue is when loading the patterns, the PATTERNS_PATH was hard-coded to "./git_vuln_finder/patterns" and this path changes when installed; therefore, it would not load any patterns to search against. The path needs to be loaded dynamically: os.path.dirname(os.path.abspath(_ file _)) + "/patterns"

Once I made the change, git-vuln-finder started to return results. I have opened a pull request to resolve issue #8.

Thanks!

[adulau]

Thank you!